Cave Paintings

Have you ever noticed how often Cavemen/Prehistoric comics have gotten painted covers over the years?
Even when not fully painted, they often incorporate painted elements in the colouring and background, as in the first two covers here -

One might almost think that there's an industry "Cave Painting" joke among editors.

Which do you think are my favorites?
You know i've got some - cave comics are home to all kinds of Odd, as certainly hinted at in some of those covers.

(In case you didn't guess - Yeah, i'm teasing another series topic)